WASHINGTON (CNN) -- The war in Iraq again became a focus of the presidential race Monday with the leak of a document from a former top U.S. commander who questioned the Army's preparedness.

Army Lt. Gen. Ricardo Sanchez wrote a memo in December 2003 in which he complained to top Army officials about a shortage of spare parts, lack of protective gear and poor readiness rates for Army weapons in Iraq.

The memo was leaked to the Washington Post, which first reported it in Monday's editions. CNN has since seen a copy of the memo, dated December 4, and also obtained a December 13 response from Gen. George Casey, then vice chief of the Army.

Casey has since replaced Sanchez in Iraq.

The leaked Pentagon document brought fresh accusations from Democratic presidential candidate Sen. John Kerry. He complained in Florida that President Bush's "mismanagement" of the Iraq war has left the United States less secure than it should be.

In a later speech in New Jersey, Bush largely ignored the Iraq war and instead reminded voters of the terrorist attacks of September 11, 2001.

The Sanchez memo said, in part, "I cannot continue to support sustained combat operations with rates this low." He was referring to the Army's readiness rates, which measure unit strength and how well equipment has been maintained.

The rate had fallen to 84 percent for Abrams main battle tanks, 85 percent for Bradley armored fighting vehicles and between 63 and 72 percent for Army helicopters.

At the time, Sanchez noted that the Army was struggling to maintain even those relatively low readiness rates and warned he could not ensure sustained combat operations could continue if the problem was not fixed.

Army officials have acknowledged that there were challenges in getting adequate supplies to troops in Iraq but say the problem was quickly solved.

"I share your concern about our Army's operational readiness and force protection posture," Casey said in his reply to Sanchez.

Monday, an Army official with direct knowledge of the situation said, "Any concerns raised by the general have been addressed."

However, last week a group of 18 soldiers refused orders to take part in a fuel convoy in Iraq because they feared their equipment was not properly maintained and did not have adequate safety equipment.

The Army called that an isolated incident and initiated an investigation. (Full story)

Vehicle readiness rates are now better than 90 percent, thanks to improvements in the delivery of spare parts. The helicopter readiness rate is 75 percent, an Army official said. Both numbers are within the Army's required level.

At a rally in West Palm Beach, Kerry said that after the Sanchez memo was sent, "George Bush went out and told the American people" that the troops were properly equipped.

"Despite the president's arrogant boasting that he's done everything right in Iraq and that he's made no mistakes, the truth is beginning to come out, and it's beginning to catch up with him," Kerry said.

Bush did argue in December, and has argued since, that the troops were properly equipped. It was not immediately clear whether the president knew about the Sanchez memo.

Bush campaign officials have criticized Kerry for voting against an $87 billion supplemental spending bill for Iraq and Afghanistan, saying it was a vote against important equipment for troops.

Kerry disputes the characterization, saying he never opposed support for troops but did disagree with the final version of the bill because of how it would be funded.

He had previously voted for an $87 billion spending bill that would have paid the cost, in part, through a roll-back of tax cuts for the wealthiest Americans. That measure was defeated.

Kerry said at the rally that Bush continues to "mislead America."

"Let me tell you something that I learned when I fought in Vietnam: Listen to the troops and give the troops the equipment that they need," Kerry said.

Bush spoke to supporters in Marlton, New Jersey, saying the United States needs "a president who defends America and fights for the middle class."

Bush turned around an argument Kerry frequently uses. Kerry often says Bush has alienated allies and entered Iraq without a broad coalition, noting that 90 percent of the coalition casualties have been Americans.

But Bush said Kerry has alienated allies because "he never shows respect for some of the 30 nations that are serving courageously in Iraq today."

Kerry said Bush must acknowledge his mistakes.

"Mr. President, when it comes to the war in Iraq, it is time to come clean and acknowledge what your military leaders have told you privately," he said. "The bottom line, Mr. President, is that your mismanagement of the war has, in fact, made Iraq and America less safe and less secure than they could have been and that they should have been today."